These Hollywood luminaries — along with a large roster of equally lofty colleagues — are referring to the substantial oeuvre of Roger Corman, the prolific producer-director whose tightly budgeted, slackly written B movies have found soft spots in many an outsider heart.

But if Corman's World: Exploits of a Hollywood Rebel has something to say about the long-lasting allure or cultural significance of trash cinema, it never quite gets the words out. Though it's enjoyable enough as far as it goes, this clip-crammed cruise through Corman's back catalog would rather skim the surface than peek below.

Focusing mainly on the first half of a six-decade career, director Alex Stapleton creates a starry-eyed and shallow portrait of a tight-fisted maverick, an astute operator whose thrill-starved audience and smash-and-grab filmmaking model was finally co-opted by the blockbuster. Dashing off cheapie 1950s horror and sci-fi, unconcerned about terrible acting or horrendous special effects, Corman cleverly targeted restless teenagers at a time when Hollywood's notion of teen fare was Judy Garland and Mickey Rooney teaming up to put on a show.

By the time the '60s rolled around, Corman had tired of drive-in fodder, learned the difference between text and subtext, and yearned to make movies that mattered.

Unfortunately, he was still a cheapskate. So when 1962's The Intruder, a serious look at Southern racism (starring a young and impossibly handsome William Shatner) became the first of his films to lose money, it was back to tacky monster suits and business as usual.

And it still is: Filmed partly on location in Puerto Vallarta where the master was shooting 2010's straight-to-Syfy Dinoshark — not to be confused with his Dinocroc or Sharktopus — Corman's World shows a man unable to stop himself from churning out bargain-basement product. A better biopic might have thought to ask why.

But Corman's real legacy was not the enjoyably cheesy Edgar Allan Poe adaptations or the naughty-nurses epics, but his generous nurturing of rising young talent. Scorsese, Ron Howard, Peter Bogdanovich, Jonathan Demme — all began their careers under Corman's wing. Employing Nicholson when no one else would, encouraging Peter Fonda and Dennis Hopper to mix bikers with drugs in Easy Rider (whose roots in Corman's The Wild Angels and The Trip are glaringly obvious), Corman was an invaluable mentor. Contrasting the crassness of his films with their maker's gentle, gentlemanly demeanor, the mentees are an ever-present chorus of gratitude and anecdote.

It's all very buoyant and breezy, a hagiographic Christmas package stuffed with bons mots but woefully lacking in analysis. Missing a golden opportunity to explore the inchoate boundary between art and exploitation, Stapleton has given us a rushed, superficial look at a career — and a man — ripe for a deeper reading. To fresh eyes, Corman's World may feel more like a meal; to the rest of us, it's merely a glance at the menu.